Process of producing calcium carbid.



Patented .lune 4, |90I. PRENNER. PROCESS 0F PRODUCING CALCIUM CARBID.

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(Application led Aug. 21, 1899.)

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UNITED STATES JOHN ZIMMERMAN AND ISEDORE S PATENT OFFICE.

. PRENNER, or cI-IIOAGO, ILLINOIS.

PROCESS OF PRODUClNG .CALCIUM CARBID.

SPECIFCATION forming part of Letters Patent No. 675,646, dated J une 4,1901.

Original application filed March 13, 1899, Serial No. 708,929. Dividedand this application filed August 21, 1899. Serial No. 727,964. (Nospecimens.)

To all whom, it may concern:

Be it known l[hat we, JOHN ZIMMERMAN and ISEDORE S. PRENNER, citizens ofthe United States, residing at Chicago, in the county of Cook and Stateof Illinois, have invented a new and useful Process of Producing CalciumCarbid, (the same being a division of the invention for which we filedan application for Letters Patent of the United States March 13, 1899,Serial No. 708,929,) of which the following is a specification.

Our invention relates to processes and methods for calcining materialsfor the production .of amalgamates or conglomerates, and is esperfectand complete fusion of the materials, so as to have a firmadhesion'thereof in the final product.

A further object is to insure the best and most perfect results yin theprocess of producing calcium carbid and to eect a great saving in heatwith an increase of the fused product.

A further obj ect is to feed the raw material so as to have it subjectedto the heat of the furnace in its advance and also to the heat of themolten material as it flows downward over the raw material beingadvanced; and other objects and purposes will appear from an examinationof thedrawings and from the following description.

The apparatus for carrying out theinvention as to the process 'andmethods thereof and the various steps involved is shown in theaccompanying drawings, in Which- Figure l is a vertical sectionalelevation of a furnace constructed and adapted for use in our invention;Fig. 2, a vertical sectional ele- 5o vation of a portion of the furnace,taken on vline 2 of Fig. l; and Fig. 3, a sectional detaily vviewrof amodification hereinafter described.

In the production of calcium carbid by the electrosmelting process asheretofore practiced it is well known that there are various objectionsand disadvantages attending the same, one of which is awaste of heat,due to the fact that in theold way the process has to be carried onintermittently, thereby preventing the entire heat of the arc from beingutilized. Furthermore, with the old type of furnace and process theinterior of the furnace had to be accessible, with 'the result thatconsiderable waste was entailed by such construction from theVconsequent imperfect fusion of the materials arising from the loss ofheat and radiant energyin opening up the furnace.

The principal object of our invention, therefore, is to provide asimple, economical, and efficient process for the production of calciumcarbid and in and by which the lime, carbon, and binder will becompletely and effectually reduced to a molten condition and fusedtogether. n

A feature of our invention is in the provision for feeding the mixturefrom below, so that as the mixture is fed to the arc it completely fillsthe space and utilizes the entire heat of the are. A further featureisthe provision for feeding the raw material from below upward whollywithin the interior of the furnace-chamber and beneath and in line withthe electric arc.

Another feature is in having the material as it is fed forward oradvanced in a confined state subjected to the heat of the furnace andalso to the heat of the molten material.

. These features, together with others, will more fully hereinafterappear in the description of the apparatus and process.

In constructing an Lapparatus in accordance with and to carry out ourimprovements and invention we provide a furnace, as shown in Figs. l and2, having inclosing Walls A of any desired kind of refractory material,such as fire-brick. Introduced through openings in the side walls of thefurnace, andk preferably near the upper portion thereof, aretwo IOOelectrodes Band B', arranged so as to form an arc b, into which amixture of -lime and carbonwith a suitable binder, may be fed. It ishighly desirable to have means for adjusting the electrodes to obtainthe correct arc aswell as to compensate for the consumption of theelectrodes. In order to accomplish this result, we provide brackets C,which are secured to the furnace-walls and 1o provided withadjusting-screws c, adapted to contact the electrodes and push the samein whenever desirable or necessary. To furnish current for the arc, weprefer to provide a dynamo D of the alternating type and conneet itspoles with each electrode by means of the wire cables d and d. It willbe noticed from an inspection of the drawings that the arcvformcd bythese electrodes is practically a rectangular arc, and in order to `fillv zo it completely andprevent the waste radiant energy or calorific raysit is desirable to feed the mixture of lime and carbon into the arc in arectangular form and of substantially the 4same size as the arc. Thiscannot be done by feeding it in loose form, for if granulated -it wouldflow away before reaching the arc'. It is therefore desirable that themixture of lime and carbon, with a suitable binder-such as borax,graphite and iron, or

3o molasses-should be formed in a pasty condition by proportionatequantities of the ingredients and compressed automatically, 'so that itmay be fed to the arc and fall away as soonas smelted. In order toaccomplish this result, we provide what we term a feedingchamberE,wh-ich is preferably arranged u nderneath andin line with the arc. Thedischarge e of this feeding-chamber is smaller in' diameter than themain portion and is also .go-.rectangular in cross-section and about thesame as the desired arc, so that as the feeding' and compressing screw Gis rotated in the direction of the hands of a watch the material is fedforwardly and compressed as it passes through the discharge-opening. Itwill be noticed from an inspection of Fig. l that the discharge-openingof this feeding-chamber' is arranged a slight distance away from thearc, which distance should be sufficient 5o to bring the opening outsideof the smeltingpoint and so that the compressed stack or column of mixedlime, carbon, and binder may enter the arc and be smelted by the time ith'as reached the upperportion thereof, when it falls away and, allowsthe following material to be acted on, all in a continuous manner. Therotating feed-compressingscrew is operated by means of a shaft g, asprocketwheel g', and a sprocket-chain g2, connected 6o with any primemover, such as a drivingshaft, an engine,a motor, or other mechanism.

Tosupply the mixture of lime, carbon, and bin'derto thevcompressing-chamber, We -provide its lower portion with lan inclinedchute H1, having al hopper h at the upper portion thereof, into' whichthe mixture may be shoveled. .This hopper, it will be understood, can

be of any size to hold any desired amount of material, so that theprocess can be carried on continuously, or until the material isconsumed.

It is desirable that the resultant product of calcium carbid may bewithdrawn from the furnace without in any way interfering with theoperation thereof. In order to accomplish this result, we provide thelower part of the furnace with a movable receptacle I, having twochambers i and fi', separated by means of the partition 2. When themachine is in operation, the chamber I is the first one arranged underthe arc so that the molten mixture may flow down 'and be caught therein.

As soon as this chamber is filled the receptacle is pulled over on itswheels i3, so that the second chamber 'i' is brought under the are, andvwhile this chamber is being filled! the first chamber is being emptiedwithout in anyway vinterfering with the process of reduction orpermitting the cold external air to enterthe l furnace.

p In Fig. 3 we have shown an apparatus for carrying out the process ofour' invention, in which a feeding-chamber K is arranged at an inclineto the arc,vwith its compressing discharge-opening 7c vertically u nderthe arc and nace. The apparatus has a hopper L,attachfed directly to theouter end of the compressingchamber,for feeding the raw material intothe feeding and compressing chamber, to be cary ried upward therein andhave a direct feed in line with the arc from beneath theV are, as

required for the process of the invention.

An important and essential feature which enters into the constructionand operation of our process is found in the compressing and feeding ofthe raw material to and between the electrodes from below an d in linewith the' arc of the electrodes, and this feature or step y in ourprocess and invention is had b'y and its receiving end outside of thewalll of the'furnace, for attachment of th'e drivingspro'cket- E wheello of the feeding and compressing screw, A so as to be operated fromoutside of the fur- IOO IIO

through the location of the feed-ing duc'tor A. chamber and thecontracted neck thereof and the feeding device therefor which operateswithin such duct or chamber, so that theira'w material will bev forcedupward in' a direct' line with the electric arc. The raw material iscompressed as itis forced through the neck land formed into the shape ofa continuous cake or core,which at its projected endcomes `between andis subjected to the arc of the electrodes and is thereby smelted for themol'- ten material to flow back over the end of the' cake or core anddown and over theside of the feeding duct or chamber, constitutingY amaterial step or feature in the carrying lout of our process andinvention.

The feed duct or chamber is located laterally within the body of thefurnace', subject to the heat of the arc', so' that such' duct orchamber becomes heated from the heat of th'e furnace and arc andtransmits heat tothe' raw material, and this transmitted heat is inaddition to the heat from the molten material which iows over thechamber and adds its heat to the raw material, thereby subjecting theraw material to the combined heat of the furnace and of the moltenmaterial in the process of reduction of the raw material and theproduction of the calcium carbid.

The plastic raw material as it is forced from the chamber gathers heatfrom the furnace and from the molten material and by the progressiveadvance toward the electric arc under the heat to which it is subjected,which heat increases as the arc is approached, is brought to a highdegree of heat, by which aperfect, thorough, and complete combination ofthe component parts ot' the carbid is insured at a great saving andeconomy of heat.

The body of the cake or core as it is being compressed and formed in theneck and the raw material Within the chamber are prevented from anyintermixture with the moiten material by such material flowing down andover the neck and forming a seal at the neck against any entrance of thematerial into the duct or chamber, and at the same time such sealingdoes not interfere in the least with the advance of the cake or corethrough the neck, as the material being in a molten state will notadhere to the neck around the cake or core sufficiently firm so as notto be broken by the advance of the cake or core.

We claim-V l. The process herein described of producchamber of anelectric furnace beneath the electrodes a continuous mass of rawmaterial, mixing and compacting the mass in its upward passage whilesubjected to heat Within said chamber, compressing the mass at its pointof ejection from the confined state, thereby forming a continuous cakeor core of raw material beneath the electrodes, continuing the upwardpressure on the raw material, and feeding the thus-formed cake or corein a direct line between the electrodes, substantially as described.

2. The process herein described of producing calcium carbid, whichconsists in pressing upwardly in a confined state within a closedchamber of an electric furnace beneath the electrodes a continuous massof raw material, mixing and compacting the mass in its upward passage,upwardly discharging the material from a confined state beneath and indirect line with an electric arc, subjecting

